Also keep in mind that the CCGA column length tolerance is at minimum +/- 0.13mm from most part manufactures and they don't collapse in the same way as a BGA, therefore the paste height deposit could be critical in some rare circumstances. Board warp is another issue.
We use 0.127 mm (0.13mm) stencil thickness for all of our boards, with or without the CCGA:s and we don't have any issues with CCGA from 684 to 1680 columns. We produce both RoHS and non RoHS. The solder joints are never as shiny and pure with no_lead soldering compare to leaded process, yet still ok. Make sure that you temp probe your CCGA since their heavy mass will "eat up the temp".
BTW, voids are acceptable if it not "to big". Ref. IPC Standard 7095 "Design and Assembly Process Implementation for BGAs." But it should also work for CCGA:s. Perhaps others can correct me on this one.
Check this out: http://www.actel.com/documents/CCGA_board_level_testing_report.pdf
Sincerely, Mika
reply »